How to shut off the sun?
July 17, 2015 11:16 AM Subscribe
Hi. When I'm walking around, the sun is unpleasantly bright and hot, which makes me wonder: How much stuff, and what type of stuff, would we have to dump into the sun in order to stop fusion from happening? Or is there no such amount of anything?
If we dumped a bunch of iron in there, would that shut it off, or would it just turn into a red giant? What if we put more iron in there? Or some other element?
If we dumped a bunch of iron in there, would that shut it off, or would it just turn into a red giant? What if we put more iron in there? Or some other element?
Fusion happens because an excess of stuff! The mass of the sun produces so much gravity that the very components of the hydrogen atoms are crammed together and release energy. The transition to red giant happens because all the hydrogen is used up, so I don't think it's possible to add anything that would stop the fusion. You would have to remove mass from the sun until it because more like a planet, and then all the other planets would fly off into space. Not that it would matter because without the sun's rays we'd be dead pretty quickly anyway.
posted by wnissen at 11:30 AM on July 17, 2015 [1 favorite]
posted by wnissen at 11:30 AM on July 17, 2015 [1 favorite]
In reality stars only shut down when they run out of fuel. Even adding a ton of iron wouldn't remove any of the existing hydrogen, etc so it's hard to say. Also, it would take like a solar mass of iron, which is a lot of iron. Ultimately the thing that makes stars work is gravity and not just their temperature and adding mass isn't going to reduce the gravity pulling the star into itself.
posted by GuyZero at 11:31 AM on July 17, 2015
posted by GuyZero at 11:31 AM on July 17, 2015
Best answer: Nope, you can't dump more stuff in to turn off the fusion. All of a star's fusion happens in the core of the star. Adding more stuff will just add mass to the star, increasing the rate of fusion.
Your best option is to wait. Eventually the sun's core will run out of hydrogen. When that happens, it'll shrink until it's hot/compressed enough to start burning helium. That will start the Red Giant phase of the sun's life. It won't be as bright then, but on the downside the sun will have grown so large that the Earth will be absorbed.
Your other option would be to build a black-hole nearby the sun to bleed away the sun's matter. If you could steal enough, the sun would be too small to support fusion and would basically turn off. Of course you now have a black hole with a huge accretion disk that will be pumping out all sorts of nasty radiation and what-not.
Alternately, you could set up a black-hole assembly farm. Create millions of little black-holes and shoot them through the sun. You'd have to make sure the black-holes are moving fast enough that they leave the solar system, but slow enough that they pick up some of the sun's mass on the way through. That ought to work.
posted by Eddie Mars at 11:34 AM on July 17, 2015 [22 favorites]
Your best option is to wait. Eventually the sun's core will run out of hydrogen. When that happens, it'll shrink until it's hot/compressed enough to start burning helium. That will start the Red Giant phase of the sun's life. It won't be as bright then, but on the downside the sun will have grown so large that the Earth will be absorbed.
Your other option would be to build a black-hole nearby the sun to bleed away the sun's matter. If you could steal enough, the sun would be too small to support fusion and would basically turn off. Of course you now have a black hole with a huge accretion disk that will be pumping out all sorts of nasty radiation and what-not.
Alternately, you could set up a black-hole assembly farm. Create millions of little black-holes and shoot them through the sun. You'd have to make sure the black-holes are moving fast enough that they leave the solar system, but slow enough that they pick up some of the sun's mass on the way through. That ought to work.
posted by Eddie Mars at 11:34 AM on July 17, 2015 [22 favorites]
What If addresses this, coming to the same answer as everyone else. (No amount of adding stuff will help, though if you turned it into a black hole, it would stop radiating except for when any matter falls into it)
posted by aubilenon at 11:41 AM on July 17, 2015 [1 favorite]
posted by aubilenon at 11:41 AM on July 17, 2015 [1 favorite]
What if you added antimatter?
posted by Faint of Butt at 11:49 AM on July 17, 2015 [1 favorite]
posted by Faint of Butt at 11:49 AM on July 17, 2015 [1 favorite]
What if you added antimatter?
You'd blow it up, right, not slow it down? -- assuming non-negligable quantities of anti-atoms even exist anywhere and if so could be manipulated.
posted by aught at 11:55 AM on July 17, 2015
You'd blow it up, right, not slow it down? -- assuming non-negligable quantities of anti-atoms even exist anywhere and if so could be manipulated.
posted by aught at 11:55 AM on July 17, 2015
i would try stick a solar mass neutron star in there. i think you might end up with a (cold, dark) two solar mass neutron star. although it would likely be a bit messy until it all settled down.
(mess being supernova-like i guess)
posted by andrewcooke at 11:58 AM on July 17, 2015 [1 favorite]
(mess being supernova-like i guess)
posted by andrewcooke at 11:58 AM on July 17, 2015 [1 favorite]
You could stop fusion by reducing the density / pressure at the core of the sun. The only way to do that by adding something would require you to also vastly expand the volume of the sun. Some sort of anti-gravity repulsive singularity at the core of the sun would do that. It would also destroy the solar system in a slow-motion nova.
posted by blue_beetle at 12:21 PM on July 17, 2015
posted by blue_beetle at 12:21 PM on July 17, 2015
Oh, and you could also add a worm-hole within the sun that would relocate a lot of the sun's mass to somewhere else in the universe. That would also screw up fusion.
posted by blue_beetle at 12:22 PM on July 17, 2015
posted by blue_beetle at 12:22 PM on July 17, 2015
I'm pretty sure the answer to this question involves mass drivers and a shitload of high-SPF sunblock.
posted by mkultra at 12:40 PM on July 17, 2015
posted by mkultra at 12:40 PM on July 17, 2015
Best answer: You could do it by adding a mass of any element with enough angular momentum to cause the sun to spin up so fast that the pressure due to gravity at the sun's core was significantly reduced, thereby reducing the rate of fusion.
It turns out there is a paradoxical population of long-lived ~solar mass blue-white stars found only in densely packed globular clusters the existence of which has recently been explained in terms of very rapid spin which is a consequence of a close encounter with another star that stripped away the mass of dust and gas during the disk stage of formation and allowed the star to attain and sustain spin rates which would otherwise have been damped down by magnetic and gravitational interactions with the disk and the planets which would have formed from that disk.
For the Sun, you might accomplish this by adding gas in a narrow, high velocity jet which was pointed very much off-center.
Interaction with the planets (mainly Jupiter) and their magnetic fields would probably undo this in maybe not too long, and in that case you'd end up hotter than you would have been.
posted by jamjam at 1:14 PM on July 17, 2015 [2 favorites]
It turns out there is a paradoxical population of long-lived ~solar mass blue-white stars found only in densely packed globular clusters the existence of which has recently been explained in terms of very rapid spin which is a consequence of a close encounter with another star that stripped away the mass of dust and gas during the disk stage of formation and allowed the star to attain and sustain spin rates which would otherwise have been damped down by magnetic and gravitational interactions with the disk and the planets which would have formed from that disk.
For the Sun, you might accomplish this by adding gas in a narrow, high velocity jet which was pointed very much off-center.
Interaction with the planets (mainly Jupiter) and their magnetic fields would probably undo this in maybe not too long, and in that case you'd end up hotter than you would have been.
posted by jamjam at 1:14 PM on July 17, 2015 [2 favorites]
You could lower the gravitational constant G, that would do it.
posted by ryanrs at 3:20 PM on July 17, 2015 [1 favorite]
posted by ryanrs at 3:20 PM on July 17, 2015 [1 favorite]
You could lower the effects of the sun locally by setting off a whole bunch of nuclear bombs causing a nuclear winter. This one has the advantage of actually being achievable with current technology.
posted by Confess, Fletch at 3:30 PM on July 17, 2015
posted by Confess, Fletch at 3:30 PM on July 17, 2015
Wikipedia: "In the movie Sunshine, the Sun is undergoing a premature death. The movie's science adviser, scientist Brian Cox, proposed "infection" with a Q-ball as the mechanism for this death, but this is mentioned only in the commentary tracks and not in the movie itself."
posted by Cool Papa Bell at 6:12 PM on July 17, 2015
posted by Cool Papa Bell at 6:12 PM on July 17, 2015
A throwaway plot point from one million years after the events of Babylon 5 (spoilers for a 20-year-old TV show -- dear god, 20 years, how did that happen?) had Sol going nova far earlier than it would have normally. I forget if this was actually canon or just an inference someone made at the Lurker's Guide, but opening hyperspace portals within the sun itself would vent enough mass to alter a star's lifespan. Open enough of them, or a single one large enough, and I imagine that a determined solicide could avoid that messy nova business altogether.
Assuming of course that 1) hyperspace exists, 2) you can make portals into it, and 3) you can do so at a distance.
How To Destroy The Earth has some clever strategies you could probably adapt for getting rid of that awful radiation leak in the sky. "Make no small plans" is a philosophy I can wholeheartedly support.
(After posting, aww crud, blue_beetle beat me to it.)
posted by Mrs. Davros at 1:50 PM on July 18, 2015
Assuming of course that 1) hyperspace exists, 2) you can make portals into it, and 3) you can do so at a distance.
How To Destroy The Earth has some clever strategies you could probably adapt for getting rid of that awful radiation leak in the sky. "Make no small plans" is a philosophy I can wholeheartedly support.
(After posting, aww crud, blue_beetle beat me to it.)
posted by Mrs. Davros at 1:50 PM on July 18, 2015
Remember that the sun radiates energy not because it's undergoing fusion, but simply because it's very hot. Fusion is just the mechanism that keeps it hot.
If all fusion suddenly stopped within the sun, it would still keep shining for millions of years.
posted by teraflop at 4:41 PM on July 18, 2015
If all fusion suddenly stopped within the sun, it would still keep shining for millions of years.
posted by teraflop at 4:41 PM on July 18, 2015
Best answer: Stars are an impressively consistent and stable phenomenon in our universe. As noted above the Sun glows because it has hydrogen nucleons ready to be fused into helium, and enough gravity to squeeze the hydrogen together hard enough to make that fusion occur. Adding stuff to the Sun doesn't get rid of the hydrogen or lessen the gravity, so as a way to turn the Sun off adding stuff is a pretty poor strategy.
Most of the more dramatic things you could add, such as a small black hole or neutron star, will have the effect of increasing the rate of burning (as well as other nastiness) and make your day worse instead of cooler.
A much simpler strategy would be to remove the Earth from the Sun's neighborhood. You could do this with a well aimed planetary mass black hole to kick Earth out of its orbit. You would want to make sure the end result is solar escape velocity, because if it isn't you will probably get really warm when the now cometary Earth re-approaches on an orbit that will probably have a much lower perisol than 1 A.U.
Or you could take a cue from classic SF. In Heinlein's Have Spacesuit Will Travel a galactic civilization decides to sanction a nasty alien race by "rotating" their planet in the 4th dimension so that, like a flatland inhabitant who is rotated in the vertical dimension, it no longer shares anything but a small intersection with our space. Since the galactic civilization doesn't bother to rotate the star too, this is considered a death sentence by cryogenic solitude.
posted by Bringer Tom at 4:45 PM on July 18, 2015
Most of the more dramatic things you could add, such as a small black hole or neutron star, will have the effect of increasing the rate of burning (as well as other nastiness) and make your day worse instead of cooler.
A much simpler strategy would be to remove the Earth from the Sun's neighborhood. You could do this with a well aimed planetary mass black hole to kick Earth out of its orbit. You would want to make sure the end result is solar escape velocity, because if it isn't you will probably get really warm when the now cometary Earth re-approaches on an orbit that will probably have a much lower perisol than 1 A.U.
Or you could take a cue from classic SF. In Heinlein's Have Spacesuit Will Travel a galactic civilization decides to sanction a nasty alien race by "rotating" their planet in the 4th dimension so that, like a flatland inhabitant who is rotated in the vertical dimension, it no longer shares anything but a small intersection with our space. Since the galactic civilization doesn't bother to rotate the star too, this is considered a death sentence by cryogenic solitude.
posted by Bringer Tom at 4:45 PM on July 18, 2015
This thread is closed to new comments.
posted by Confess, Fletch at 11:19 AM on July 17, 2015 [1 favorite]